AI: THE SOMNIUM FILES - nirvanA Initiative is a thrilling adventure game developed by Spike Chunsoft. In this sequel to the critically acclaimed AI: The Somnium Files, players follow the newly-appointed Special Agent Mizuki and her AI partner Aiba as they attempt to solve the bizarre Half Body serial killings. The game is available for Windows and is a full version.

The story begins when a right half of a corpse was discovered six years ago under mysterious circumstances. The left half of the body was never found until six years later when it was discovered completely fresh with no signs of decay. The victim seemed to have been alive until just recently. The game provides players with the opportunity to help Special Agent Mizuki and her AI partner Aiba solve the mystery of the Half Body serial killings and bring the killer to justice.